Image using only Hue. *UNSOLVED*

Hi I'm new here.

I'm making an Infographic about colour and wanted to show the how Hue, Saturation and Brightness can make up colour. I want to have a set of example images each using only Hue, Saturation of Brightness. I'm starting off with Hue and I have my example image however I cant seem to set the image to have full Saturation and Lightness with only the Hue varying.

PS has the Hue/Saturation sliders that do exactly this, demoing how those sliders affect your pic seems the obvious answer.

The saturation slider doesn't only affect saturation...
It also affects brightness, it seems the only way would be to do it manually but there must be hundreds of thousands of pixels in the image I've chosen so that's not an option...